The present invention relates to high frequency filters and, in particular, to a distributed, thin film lumped element band-pass filter theoretically capable of operation at frequencies in the range of 800 MHz to 10.0 GHz.
Varieties of thin film devices have been constructed for high frequency circuits. Most have been directed to microwave applications. Some devices, such as discrete delay line assemblies, have been constructed for higher frequency applications. Delay lines are frequently used to adjust timing inconsistencies at complex circuitry mounted to complex printed circuit boards. Examples of some discrete, multi-layer, delay line devices constructed on ceramic substrates are shown at U.S. Pat. Nos. 5,030,931; 5,365,203; and 5,499,442.
The subject invention provides a discrete, distributed, lumped element, thin film band pass filter. Alternative multi-layer, filter configurations are constructed on ceramic substrates between shielding layers. Resonator, strip line, grounding and necessary termination layers are connected with solder filled vias that extend between the substrates and interconnect elements at the layers.